On the average, every fifth person in the age group between 20 and 70 years needs treatment because of diseased veins, and particularly every third person suffers from pathological vein changes which, although they do not yet need invasive treatment, nevertheless cause troubles and may need treatment in the future. In general, the cause of this often is a genetically caused weakness of the connective tissues, which leads to a relaxation of the walls of the veins and therefore to a lack in the ability of the venous valves to close. This results in a reduction of the venous return flow from the legs into the body.
Supportive measures are known in the form of so-called pressure hose, but preventive measures are unknown, in particular in connection with people who, because of their occupation, perform predominantly sitting or standing tasks. In these cases it is suggested to move the legs as much as possible in order to increase the venous return flow from the legs back into the body by promoting the so-called foot and calf muscle pump. This is aided to a great extent by walking barefoot, however, the shoes which are customary these days have a rather disadvantageous effect.
Walking shoes are known, wherein resilient layers in the form of supports are used in the heel area. But these known resilient layers are merely intended to compensate the specific overloads occurring during walking, or at least to assist in partially preventing them (German Patent DE 39 02 872 A1).
In connection with an orthopedic inner sole for shoes known from German Patent DE 87 00 681 U1, cushioned, layers are also embodied as an arched padding, which protrudes upward above the covering layer of the soles, and is provided in one piece with a large surface for support and pressure distribution in defined areas of the foot. An inner sole for a shoe is moreover known from German Patent DE 35 08 582 C2, which has a resilient padding in the area of the reflex zones of the foot. This padding has a symmetrically or asymmetrically concavely arched, or respectively bulged shape, and is essentially circular when viewed from above, and is therefore used for stimulating the nerves in these reflex zones. The reflex zones in the feet have an exclusive effect on the nervous system which, inter alia, affects the arterial blood supply of defined organs. No remedy for the problems of venous outflow of blood mentioned at the outset, in particular in the area of the lower leg, can be achieved by this.
An inner pole for a shoe is also known from U.S. Pat. No. 4,633,877, wherein an intermediate sole is put together from individual elements over its entire surface, of which a segment, which is arranged in the forefoot joint area, is divided into individual sub-segments. The sub-segments adjoin each other in the transverse direction of the sole surface. The individual segments and sub-segments are each flat and of the same thickness. By means of a differently resilient embodiment, this known inner sole for a shoe is used for the differentiated support of the foot, wherein the position of the segments takes into consideration the position of the corresponding bones of the foot.
A similar purpose is sought in European Patent, EP 0 316 289 A, wherein the inner sole of the shoe is provided with hollow spaces distributed over the sole surface, which can be filled with a resilient material corresponding to the shape of the foot. Such an inner sole for a shoe is used for orthopedic correction.